Magnetic interrupter



May 29, 1934. A. T. MACEY MAGNETIC INTERRUPTER Filed June 8, 1933INVENTOR.

g 'a @fag ATTORNEYS iff/mf 7? if@ C@ Patented May 2.9, 1934 UNITEDSTATES MAGNETIC INTERRUPTER 'Arthur T. Mace, East Cleveland, Ohio,assignor to The Radiart Corporation, Cleveland, Ohio, a

corporation of Ohio Application June 8, 1933, Serial No. 674,885

5 Claims.

This invention relates as indicated to magnetic interrupters and moreparticularly to magnetic interrupters of the character employed for thepurpose of converting constant unidirectional current to pulsatingand/or alternating current.

It is among the objects of my invention to provide a magneticinterrupter and the means for supporting the same so as to reduce to aminimum the hum and/ or vibration usually incidental to the operation ofapparatus of this character.

It is a further object of my invention to provide a magnetic interrupterin which the several parts necessary to be assembled to form thecompleted apparatus may be formed and so assembled in such manner andwith such facility as to reduce the manufacturing cost of the apparatusand Without a sacrifice of quality in the finished product. I

A further object of my invention is to provide an interrupter of thecharacter described in which the electromagnet or more specifically thearmature thereof, 'as well as the vibratory reed, are both movable, atleast to a limited extent whereby certain desirable characteristicsincidental to the operation of the device are secured, particularly whenemployed in conjunction with a transformer.

Another object of my invention is to provide a magnetic interrupter ofthe character described particularly applicable to be used for thepurpose of low voltage unidirectional current to high voltage pulsatingand/ or alternating current for use in the operation of radios, luminoustube lamps and the like.

Other objects of my invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention,then consists of the means hereinafter fully described and particularlypointed out in the claims.

The annexed drawing and the following description set forth in detailcertain mechanism embodying the invention, such disclosed meansconstituting, however, but one of various mer chanical forms in whichthe principle of the invention may be used.

In said annexed drawing:-

Figure 1 is a transverse sectional view of an apparatusconstructed inaccordance with the principles of my invention taken on planessubstantially indicated by the line 1- 1 of Figure 2; Figure 2 is atransverse sectional View of the apparatus illustrated in Figure 1 takenon a plane substantially indicated by the line 2-2; Figure 3 is afragmentary sectional View of the apparatus (Cl. 20G-90) illustrated inFigure 1 taken on a plane substantially indicated by the line 3 3; andFigure 4 is a diagrammatic representation of the apparatus illustratedin the previous figures shown in conjunction with a transformer.

I Referring now more specifically to the drawmg and more especially toFigures 1 and 2, the magnetic interrupter presently to be described is,according to the principles of my invention, mounted within andsupported by an inner box generally indicated at l, preferably formed ofnon-magnetic material. The base 2 upon which the interrupter is mountedforms one side of this inner box. The inner box 1 is contained withinthe outer box generally indicated at 3, also preferably formed of.non-magnetic material. The boxes 1 and 3 are spaced apart and separatedby means of a plurality of slabs of some suitable soft resilientmaterial 4, such as sponge rubber.

Enclosing the magnetic interrupter in the above defined manner reducesto a minimum the vibration and hum usually incidental to the operationof apparatus of this character and supporting the interrupter within theclosed space defined by the several boxes and layers of insulatingmaterial ,is effective to exclude air from the space surrounding theinterrupter so that the harmful effect of any arcing which may takeplace at the contacts is reduced to a minimum.

The magnetic interruptor proper comprising my invention consists of anelectro-magnet, generally indicated at 5 which consists of a core 6 andan electro-magnet coil, generally indicated at 7,- whch, forconvenience, is Wound on the core 6.

Positioned in substantial parallel relation to the coil 'i are avibratory reed, generally indi cated at 8 and a pair of contact armsgenerally indicated at 9 and l0.

The reed consists of a main blade 11 and an auxiliary blade 12 securedto one end thereof, 95 such blades carrying contact members of the usualtype on their opposite'faces. The core 6 of the electro-magnet ispreferably terminally bent laterally, as at 13, and extends adjacent thefree end of the reed to which a block of magnetic material, or anarmature, generally indicated at 14, is secured. The core 6, the reed 8and the contact carrying blades 9 and -10 are all supported at one endonly, in a pillar formed by the ends of such members and alternatelayers of insulating material such as 15. 4

In order to facilitate manufacture and assembly of the parts andparticularly in insulated relation, the base 2 is provided with a pairof spaced apertures 16 into which are set close-iit- 110 ting pins 17formed of insulating material. The several elements which are supportedat their one end in the pillar and in non-conductive relation areprovided with apertures which closely t the pins 17 so that these pinsserve as the means whereby the several elements forming the supportingpillar are maintained in predetermined relation. Centrally of the pins17, the various elements forming the supporting pillars are providedwith enlarged axially aligned apertures through which a bolt 18 extendsand by means of which the several components of the pillar are rigidlysecured to the base 2.

By employing the locating pins 17 of insulating material for maintainingthe several parts in predetermined relation and by passing the securingbolt 18 through an enlarged aperture in the pillar, it is not necessaryto provide insulating means other than the air space between the sidesof the bolt and the several blades and reed. In this fashion, the costof manufacture is considerably reduced and the assembly of the devicegreatly facilitated. e

In order to provide electrical communication between an incoming leadsuch as 19 and the reed 8, I may prefer to employ a block of electricalconductive and magnetic material 20, which has the central aperturetherein either threaded or in such close fitting engagement with thebolt 18 as to be in electrical and magnetic communication therewith. Byproviding a plate 21 of conducting material under the head of the bolt18 and connecting the lead 19 to such plate, communication with the reed8 through the bolt 18 and layer 20 may be had. This makes possible aconnection to the reed which is much superior to that which could besecured by soldering or similarly securing the lead 19 directly to thereed. The plate 20 being formed of magnetic material assists incompleting the magnetic circuit for the flux generated by the winding 7,i. e., the return flux through the reed 8 is carried by the plate 20which is in magnetic communication with the bolt 18, the latter being ofmagnetic Inaterial and in contact with the core 6.

It will be noted that the reed and the electromagnet or morespecifically the core thereof, are both secured cantilever-Wise at onlyone end, which reduces the mechanical resistance of the reed tovibration so as to increase the efficiency of the interrupter.

Supporting the electro-magnet at only one end also permits theelectro-magnet to vibrate in addition to the vibration of the reed.'This also increases the efficiency of the apparatus.

Positioning the electro-magnet Iin overlying relation to the reed makespossible the arrangement of its poles in such a manner as to moreeiectively influence the reed when the magnet is energized than if suchmagnet were positioned entirely at one end of the reed.

By having reference to Figure 4, the operation of the apparatus abovedescribed will now be briefly explainedz-The lead identified in theforegoing description by the ordinal 19 is connected in the mannerpreviously explained with the reed 8 and is also connected to one sideof the winding 7 of the electro-magnet 5. This lead 19 may be connectedto one side of any suitable source of supply for a unidirectionalcurrent such as the battery 22. The contact carrying blades 9 and 10 arerespectively provided with leads 23 and 24, which are respectivelyconnected to the opposite ends of the primary winding 25 of atransformer. The other` side of the winding 7 of the electro-magnet isalso connected to one end of the winding 25 by means of a lead 26. Theother side of the battery 22 is connected by means of a lead 26a toapproximately the midpoint of the Winding 25.

The secondary winding 27 of the transformer may have any suitableresistance such as a lamp 28 connected thereacross. Assuming that thecircuit as illustrated in Figure 4 from the battery is closed,preferably by means of a switch in series in the lead 19 so as toestablish the circuit illustrated in said figure and with the parts asillustrated in Figure 4, the only path for current flow in the circuitincluding the battery is through the lead 19, magnet winding 7 and backto the battery through lead 26, winding 25 and lead 26a. This willenergize the coil 7 forming an electro-magnet of the core 6. The polepiece 13 of the core 6 will, when energized in this fashion, attract theblock of magnetic material or armature 14 secured to the end of thereed. When the reed is thus attracted to the magnet when energized, thisattraction will move the reed into contact witlthe lower blade 9,thereby shortcircuiting the coil 7 through thelead 23. The amount ofcurrent flowing in the coil 7 is, therefore, considerably reduced sothat the strength of the magnet is no longer suflcient to overcome thespring action of the reed, whereupon the reed will snap up `andover-carry into contact with the upper blade 10.

When the reed makes contact with the upper blade l0, a 110W of currentwill be established through the upper portion ofthe winding 25, but in adirection opposite to the flow of current in the lower portion of suchwinding. Vibration of the reed 8 between the blades 9 and 10 will,therefore, result in the establishment of alternating magnetic uxthreading the secondary winding 27 of the transformer.

As soon as contact between the reed 8 and the lower blade 9 is broken,the coil 7 is again energized so that the magnet reasserts its influenceon the armature 14 to move the reed back into contact with the blade 9,thereby maintaining continuous vibration of the reed between the blades9 and 10 at a rate depending upon the excitation of the winding 7, asWell as the natural period of the several moving parts of the apparatus,so that each is permitted to vibrate to a certain extent, the currentimpulse produced by the interrupter will be sharply dened so that as themagnetic lines of force incidental to the now of these current impulsesthrough the primary Winding 25 thread the secondary Winding 27, a highpotential alternating current will be generated which is particularlycharacterized by flattened tops on the nodes of the Wave produced by anoscillograph analyzing the output of the transformer.

The apparatus comprising my invention, due to its simplicity ofconstruction, low cost of manufacture, small size for a given output, aswell as the character of its output, is particularly applicable to beused in connection with apparatus such as radios and luminous tubedisplay signs. The apparatus has been demonstrated as particularlyuseful in the operation of luminous tube signs on automobile vehiclesand the like Where low potential direct current only is available. Theprinciples of my invention are, of course, applicable to a wide varietyof uses other than those enumerated and it is to be understood that theuse of the invention is not limited to the examples of its use whichhave been chosen for purposes vof illustration.

Other modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the mechanismherein disclosed, provided the means stated by any of the followingclaims or the equivalent of such stated means be employed.

I, therefore, particularly point out and distinctly claim as myinvention:

1. In a magnetic interrupter, the combination of an electro-magnetcomprising a bar-like core supported in cantilever fashion at one endthereof, a winding about said bar, a vibratory'reed arranged in parallelrelation to said core and' likewise supported at only one end, and anarmature supported upon the reed and adjacent the end of said reed, saidarmature having substantially the same cross sectional area as saidcore.

2. In a magnetic interrupter, the combination with an electro-magnet, ofa vibratory reed adjacent said magnet, said reed comprising a blade ofresilient material supported only at one end, a second blade ofresilient material secured only at one end to the free end of saidfirst-named blade, contact members carried by the opposite faces of saidreed blades, resilient blades on opposite sides of said reed andsupported only at one end adjacent the fixed end of said reed, andcontact members on the opposed faces of said last-named blades.

3. In a magnetic interrupter, the combination of an electro-magnetcomprising a bar-like core supported in cantilever fashion at one endthereof, a winding about said bar, a vibratory reed arranged in parallelrelation to said core and likewise supported at only one end, and anarmature supported upon the reed and adjacent the end of said reed, saidarmature having substantially the same cross sectional area as saidcore, said reed comprising a plurality of substantially parallelresilient blades secured together at one end only and to which saidcontact members are respectively secured.

4. In amagnetic interrupter, the combination of a supporting base, anelectro-magnet coil, a at bar core within said coil upon which thelatter is supported, a vibratory reed adjacent said coil and parallelwith said core, and means respectively supporting said reed and core atonly one end of said base.

5. In a magnetic interrupter, the combination of a supporting base, anelectro-magnet coil, a iiat bar core within said coil upon which thelatter is supported, a laterally extending pole piece on said core, avibratory reed adjacent said coil, and means supporting said reed andcore in substantially parallel relation and in cantilever beam fashionon said base.

ARTHUR T. MACE.

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